Question: Reduce to lowest terms: $- \dfrac{3}{5} \div \dfrac{4}{7} = {?}$
Explanation: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $ \dfrac{4}{7}$ is $ \dfrac{7}{4}$ Therefore: $ - \dfrac{3}{5} \div \dfrac{4}{7} = - \dfrac{3}{5} \times \dfrac{7}{4} $ $ \phantom{- \dfrac{3}{5} \times \dfrac{7}{4}} = \dfrac{-3 \times 7}{5 \times 4} $ $ \phantom{- \dfrac{3}{5} \times \dfrac{7}{4}} = \dfrac{-21}{20} $